Screw-adjusting tool



Jan- 19, 1954 w. w. HAcKETT SCREW-ADJUSTING Toor.

Filed June 8. 1949 INVFNTOR .Hbc/fer? IA/HLTER ATTORN EY Patented Jan. 19, 1954 y UNI-TED STATES PATENT-Y CFFIC-E- 2,666,350 SCREW-ADJUSTING'TOOL Walter W. Hackett, oakland, Calif. Applioatioii Juno s, 1949, serial No. 97,767

(ol. ssi-3) 4 Claims.

The-invention relates to a tool for adjustably turning a screw to a measured degree, and particularly a screw which adjustably controls the gap between mutually cooperative tappet members.

A general object is to provide a unitary screwadjusting tool which directly gauges the effective adjustment of a screw therewith. Y

A more speciiic object is to provide a tool of the character described which is applicable to a screw which adjustably controls the gap between a tappet arm and a member engageable by the arm, whereby to eliminate any need for the application of a feeler blade of known thickness in the gap for determining the size of the galp- Another object is to provide a unitary tool of the character described which may be applied and usedin a particularly effective and speedy manner.

A further object is to provide a unitary screwadjusting tool of the character described with means for releasing and resettingV a locknut for a screw to be adjusted by the tool. d

The invention possesses other objects and features of'advantage, some of which, with the foregoing,` will be set forth or be apparent in the following description of a typical embodiment thereof, and in the accompanying drawings, inY

which Y Figure'l is av perspective view of a tool embodying my invention. l

Figure 2 is a` generally sectional elevation showing the tool as applied for adjusting" the valve tappet gap of a valve-in-head internal combustion engine.

Figure 3 is a partly sectional plan view taken at the plane of the line 3-3 in Figure 2, and showing the tool as initially applied to a tappetadjustment screwV and its locknut. i

Figure 4 is a View similar to that of Figure 3 and Yshows the tool as :disposed in readiness Ifor eiecting a measured gap adjustment therewith.

Figure 5 is' a sectional View taken generally at the line 5-5 in Figure 4.

Figure 6 is a view'lshowing the tool in corresponding position to that of Figure 4 after the gap adjustment has been effected.

Figures 7 and 8 are enlarged sectional views taken at the line 1 1 of Figure 2 when the tool and tappet screw are related as in Figures 3 and" 4' respectively;

Figures 9 and 10 are enlarged plan views of a pointer member of the tool as dismounted and mounted respectively with respect to a screwdriver shank vof the tool assembly.

A tool I2 Yembodying the features'of my invention is particularly shown as applied to an ad:V justing screw I3V threadedly engaged through the endV of `an arm I4 of a rocker I4 which is intermediately pivoted on a stub-shaft I5 carried by a standard I6 extending from the head-block I1 of an internal combustion engine (not shown), said screw being releasably held in set position by a locknut IB mounted on it and normally engaging the top of the rocker arm I4. rlhe screw I3 extends transversely of the head-block I1 and its lower end (point) is provided with a ball I9 which is complementarily engaged in a terminal socket 2If provided by ay valve-opening push-rod 2l which extends through and from the head-block I1. The head-block l1 carries a spring-seated tappet valve 22 having its stem' 22 extending upwardly from the head-block for periodic engagement by an overlying contact head 23 provided at the end of the rocker arm i4" which does not carry the screw I3. Except during an unseatingv of the valve ZI, a usual gap `2l! is provided between the contact 23 and thev lopposed end of the Valve stem 22', and it is this lgapwhich is to be set or adjusted to insure the best operation of the engine.

In its present form, the tool I2 essentially com-` prises an elongated body member having a handle portion 26 extending laterally and integrally from a wider head portion 21 in alignment there,- with and'rotatively mounting a screwdriver 3| transversely therethrough near its free end. A* face 28 of the headportion 21 is at and is pro-" vided withnan arcuate angle scale 29 comprising aline of calibration marks radiating from the rotation axis of thevscrewdriver whereby the scale is concentricy with said axis; the presentr tool would usuallyvbe applied with its face 28 disposed for viewing from above, and said face may thereforeA be conveniently referred to as the upper face of the head. Preferably, and as shown, the handle 26 and thecenter of the scale arc are at opposite sides of the scale with the midpointy of the scale inthe handle line and the head generally sector-shaped to minimize its size.

The screwdriver `element-3| is mounted on the head portion 21 withrits shank 32 rotatably engaged in a bore provided through the head portion 21 in perpendicular relation to theupper head face 28 and the scale 29 thereon. The handle 34 of the screwdriver is disposed above they face 2s, while the terminal bit portion es? of the screwdriver shank 32 is disposed somewhat below stood, however, that other types of cooperative engagement might be provided between the screwdriver and a screw to be turnedly engaged by it. As particularly shown, the screwdriver shank 32 extends axially through an integral boss 36 depending from the head portion, and also extends through a bore portion provided through a guide member 38 which is xedly positioned opposite the head face 28 at the end of an arm 39 extending transversely from the point of the head portion 2. A removable spring ring 40 normally engages a peripheral groove in the shank 32 adjacent the bit 35 to prevent a dismounting of the screwdriver.

Means are provided for frictionally retaining the shank 32 in adjusted position in the head 21, said means also providing a pointer for reference to the scale 29. As particularly shown, the under face of the member 38 is parallel to the opposed upper face 28 of the head, and the shank portion between said faces mounts a longitudinally slit spring sleeve 4| which must be circumferentially spread to receive the shank and therefore rictionally grips the same while permitting relative axial and/or rotative adjustments of the sleeve and shank.

A pointer arm 42 extends rigidly from the bottom of the sleeve 4| and at a point thereof opposite the slot 4| of the sleeve, the outer part of the arm extending opposite the scale 25 for reierence thereto. Projections 43 and 44 extend upwardly from the sides of the head portion 22' at the ends of the scale 29 for engagement by the pointer 42 to limit its rotation as the screwdriver 3| is rotated while its bit engages the head of a screw to be turned, it being noted that the spring-grip engagement of the shank 32 in the sleeve 4| permits a continued rotation of the shank after the pointer has engaged the projection 43, yet provides for a swinging of the pointer by the rotating shank when the pointer is not held against turning with the shank.

While the now-described tool structure might be utilized alone for adjusting a tappet gap 2li` in a manner hereinafter disclosed, means are preferably provided for turnably engaging a locknut i8 oi a screw i3 to be adjusted. As par-v ticularly shown, the boss 36 is externally formed to complementarily t in theV handle-engaging end of a wrench socket 45 which is formed to have its other end complementarily receive a locknut I8; as is brought out in Figure 1, the handle-receiving bore portion 46 of the wrench socket 45 is of square cross-section, and the boss 36 is externally formed for complementary tted engagement in the socket bore 46. As is generally usual, the lockout I8 is hexagonal, and the nut-receiving bore portion of the socket 45 is arranged to complementarily receive the same. The wrench socket 45 is preferably one of a set having like bore portions :it whereby the tool may be applied to locknuts of diiierent sizes by mounting an appropriate socket on the boss 36. Means are preferably provided for releasably securing a socket 45 in mounted relation on the boss 36; as particularly shown, such means comprises a leaf spring 4? having its base end Xed to and beneath the head 2l with its yielding end in such spaced opposition to the boss 3B that the outside cf a mounted socket` 45 may be frictionally engaged for releasahly securing the socket to the head.

Having the appropriate wrench socket 45 mounted thereon, a present tool I2 is initially applied to an adjustment screw I3 and its locknut I8 carried by a rocker arm I4 in the relation shown in plan in Figure 3, with the socket receiving the nut for its turning therewith, and the screwdriver bit 35 engaged in the head slot of the screw. The screwdriver bit 35 is applied to the screw by sliding and turning the shank 32 to engage the bit in the screw slot, this being preferably accomplished while the pointer 42 is disposed at, or near, the zero end of the scale 29. The handle 2t of the operatively mounted tool is initially disposed for its nut-releasing swinging to then dispose it in the most convenient position for holding by a mechanic adjusting the screw; looking from above, the handle 25 would be swung in a counter-clockwise direction to the approximate position of Figure 4, for releasing the nut sufficiently to permit an adjustment turning of the screw I3. With the handle 26 Xedly held by the mechanic, the screwdriver 3| is turned (clockwise) until the gap 24 has been closed, the outer pointer end then engaging the head projection 43.

Having the gap closed and the pointer 42 engaging the stop projection 43, a return (counterclockwise) rotation of the screwdriver to a desired indication of the scale 25 while the handle is held in the gap-closing position, will eect a reopening of the gap to a distance which is measured in accordance with the angle of turning of the pointer with the screwdriver over the scale. In the case of a particular engine, the scale 29 may indicate thousandths of an inch, or other gap measurements, as determined by the pitch of the adjustment screws I3 which are usually alike for engines oi a given make. If however, it is desired to use the tool for adjusting screws of different or reverse pitch than that for which the scale 2S is calibrated, it will be understood that the calibration marks of a given tool may berreierred to an appropriate table of true gap values in terms of the indications of the pointer along the arcuate scale. Also, the scale might indicate turn angles.

As particularly illustrated, the zero point of the scale 29 is spaced from the stop 43 by an arcuate distance which corresponds to the normal lost-motion engagement of the screwdriver bit 35 in the screw-head slot, thus providing for an increased accuracy of setting or the pointer 42 in terms of the gap. Because of the provision and use in the present tool of the flat scale 23 having a relatively large radius compared with the radius of the controlled screw, whereby the length of the pointer is at least nine times that of the radius of the screw i3, it will be understood that the making of the quickly effectable gap settings therewith is as fully accurate vas may be needed in usual practice. It is also to be noted that the present relation of the scale 29 to the tocl handle 25 provides for a particularly ready observation of pointer settings by the operator holding the handle as a positioning means for the tool, while making the tool equally usable by `right-handed and left-handed operators.

It will be obvious that the present screw-adjusting tool may be used for its purposes without having a wrench socket 45 provided and utilized therewith; if an adjustment screw which is normally held set by a locknut is to be reset with the present tool, the locknut might be loosened by the application of a separate wrench thereto. It will also be understood that the pre ent tool is usable generally for adjusting ,any screw which is arranged to directly. provide a gap of desired size between an end and a referi. l l.

ence object, or to be turned through a predetermined angle. It isto be particularly noted that the present tool assures accurate gap clearance adjustments of a screw I3 controlling the gap between a rocker arm I4 and the valve stem 22 controlled by the arm, independently of any worn or pitted condition of the opposed faces of the members which would appreciably affect the accuracy of use of a usual gauging feeler blade in lieu thereof.

From the foregoing description taken in connection with the accompanying drawings, the advantages of the present screw-adjusting tool will be readily understood by those skilled in the art to which the invention appertains. While I have described the principle of operation, together with a form of my invention which I now consider to comprise a preferred embodiment thereof, I desire to have it understood that the showing is primarily illustrative, and that such changes and developments may be made, when desired, as fall within the scope of the following claims.

I claim:

1. In a tool for turning a screw to a measured degree from a predetermined initial set position, an elongated handle member providing a transverse bore for rotatively receiving the shank of a screwdriver. and having thereon an arcuate scale concentric with said bore, a screwdriver having its shank journalled in said bore and terminating in a screw-engaging means, a radial pointer carried by said shank in frictional engagement therewith for swinging adjustment thereabout and arranged rfor turn-measuring rotation therewith opposite said scale, and a stop xed on the handle member operative at a scale end for engagement by the pointer to limit the pointer rotation with the shank to a zero setting of the pointer during an initial setting of a screw engaged by the screwdriver whereby a reverse rotation of the shank to reset the screw will be directly measured from the zero setting by the swinging movement of the frictionally held pointer over the scale.

2. In a tool for rotatively adjusting a screw which is normally held in set extending position in a supporting member by a locknut mounted on its extending portion in normal screw-locking engagement with the member, an elongated handle member providing a transverse bore and a wrench socket coaxial with said bore for complementarily receiving said locknut whereby the handle member may be rocked about the screw to release or to re-lock the locknut, a screwdriver having its shank journalled and axially slidable in said bore and operatively engageable with the screw for turning it while said socket engages the released locknut against its turning, and a pointer member rotatably mounted on the shank in frictional engagement therewith for reference to a concentric scale provided by the handle member, said handle member providing a stop effectively operative at a zero point of the scale for engagement by the pointer to limit the rotation of the pointer with the shank to the zeropoint setting of the pointer with respect to the scale during an initial reference setting of the screw.

3. In a tool for turning an installed screw to a measured degree from an initial set position thereof, a member providing an elongated handle portion extending from a head portion providing a transverse bore for rotatively receiving the shank of a screwdriver and having on a face thereof an arcuate scale concentric with said bore, a head portion comprising an extension of the first head portion and disposed opposite said face in xed spaced relation thereto and providing a bore coaxial with the rst bore, a screwdriver having its shankrjournalled in said bores and terminating in a screw-engaging means and having its handle end at` the opposite side of the head extension from the head scale, a sleeve member retainedly mounted on the screwdriver shank between the head portions in frictional engagement therewith for its rotative adjustment about the shank. and a pointer member extending rigidly from the sleeve member for turn-measuring rotation opposite said scale.

4. A structure in accordance with claim 3 having the handle member providing a stop means for engagement by the pointer to limit the rotation of the pointer with the shank to a predetermined zero setting thereof vwith respect to the scale during an initial reference setting of the screw.

:1 WAL'I'ER. W. HACKETT. neferences cited in the me of this patent UNITED STATES PATENTS Number Name Date 1,575,560 Englund Mar. 2, 1926 1,681,881 4Shaw Aug. 21, 1928 2,194,069 Gagne Mar. 19, 1940 FOREIGN PATENTS Number Country Date 448,530 Great Britain June 10, 1936 

